Angiosperms are flower bearing plants that show sexual reproduction .

The flower consist of male reproductive and female reproductive parts :

Male reproductive part

It consist of stamen that has filament ,anther lobe , pollen  grain.

Female reproductive part

It consist of Ovary ,style ,stigma .

• Stigma : It is the upper portion which receives the pollen
• Style : It is the tube like structure that connects stigma with ovary .
• In ovary : Ovules are present that are attached to placenta
• Ovule
• It consist of embryo sac that has antipodal cells ,synergids and egg cell and a polar nuclei .
• It has layer of integument and nucellus .
• There is a point where integument is absent that is micropyle .
• The figure for the same is shown below :

a. Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the earth, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions.

The two most obvious benefits from commercial fishing are: 1) that it feeds the world's demand for seafood, and 2) that it has a tremendous economic impact on world GDP.

b. Because of the roles fish play in aquatic communities, and their ability to move to different environments based on changing conditions, the variety and diversity of fish species found at a given site serves as an indicator of biological integrity and water quality.

Traditionally, four types of restriction enzymes are recognized, designated I, II, III, and IV, which differ primarily in structure, cleavage site, specificity, and cofactors. Restriction enzymes that bind several sites in order to cleave exhibit several characteristics: Cleavage kinetics. Substrates with single sites are cleaved slowly and in some cases incompletely because enzymes must interact with ('bridge') two or more DNA molecules at once.

A sperm has three main parts:

1) The head of the sperm contains the nucleus. The nucleus holds the DNA of the cell. The head also contains enzymes that help the sperm break through the cell membrane of an egg.

2) The midpiece of the sperm is packed with mitochondria. Mitochondria are organelles in cells that produce energy. Sperm use the energy in the midpiece to move.

3) The tail of the sperm moves like a propeller, around and around. This tail is a long flagella that pushes the sperm forward. A sperm can travel about 30 inches per hour. 

The menstrual cycle is the reproductive cycle in a human female after puberty. The ovary releases one egg every month. The uterus also prepares itself every month to receive a fertilized egg. Various hormones are involved in controlling the cycle. The role of hormones is as follows:

1) Pituitary gland secretes Follicle Stimulating Hormone (FSH) which stimulates the development of follicle.

2) The follicle cells then secretes estrogen. Increase in the level of estrogen, stimulates the thickening of endometrium in the uterus. Also, it leads to the secretion of Luteinizing hormone (LH) by the pituitary gland which causes ovulation.

3) The level of LH increase and this is followed by increase in the secretion of progesterone and the follicles develop to form corpus luteum.

4) The corpus luteum then secrets high level of progesterone preparing the uterus for implantation. The high level of estrogen and progesterone decreases the level of FSH and LH.

5) In case no implantation occurs, levels of progesterone and estrogen decreases resulting in the breakdown of endometrium marking the beginning of menstruation.

8) After the menstruation begins, a level of FSH and LH again rises resulting in the beginning of new menstrual cycle.
 

• Mendel conducted cross-pollination experiments using several true-breeding pea lines. 
• A true-breeding line is one that, having undergone continuous self-pollination, shows the stable trait inheritance and expression for several generations.
• Mendel selected 14 true-breeding pea plant varieties, as pairs which were similar except for one character with contrasting traits.
•  Some of the contrasting traits selected were smooth or wrinkled seeds, yellow or green seeds, inflated (full) or constricted green or yellow pods and tall or dwarf plants. In these green pod is the dominant trait and the yellow pod is a recessive trait. 
• Hence, a green pod is a dominant trait in pea. 

A cross between homozygous round seeds plant (RR) and homozygous wrinkled seeds plant (rr) produced all the F1 offspring with round seeds. This is because the round shape is determined by the dominant allele. According to the Law of Dominance, in a heterozygous individual, the phenotype will be determined by the dominant allele as recessive allele is inexpressive in the presence of dominant allele.

Ascariasis is an infection of the small intestine caused by Ascaris lumbricoides, which is a species of roundworm. Roundworms are a type of parasitic worm. Infections caused by roundworms are fairly common. Ascariasis is the most common roundworm infection. In mild or moderate ascariasis, the intestinal infestation can cause: Vague abdominal pain. Nausea and vomiting. Diarrhea or bloody stools.

Antibodies are immune system-related proteins called immunoglobulins. Each antibody consists of four polypeptides– two heavy chains and two light chains joined to form a "Y" shaped molecule. ... This variable region, composed of 110-130 amino acids, give the antibody its specificity for binding antigen. An antibody is a protein that is synthesized by an animal in response to the presence of a foreign substance in our body, called an antigen. They play a great role in the immune system, and are usually found in blood and other bodily fluids. Antibodies are created by white blood cells, or more specifically, B cells.

• Cell- mediated immunity- The immunity which is mediated by T- lymphocytes by directly attaching themselves to the antigens is called cell mediated immunity.

Ringworm can be caused by the following ways:

• It spreads by skin contact with an infected person.
• It spreads from pets and cows. One should wash hands properly after playing with the pets.
• The fungus causing ringworm might be found lingering on clothes, comb, towels and brushes.
• These fungi are mainly present in the spores of soil. Coming into contact with such soil will result in an infection.

The bacteria Salmonella typhi causes typhoid. It is also called as Salmonella enterica. The mode of transmission is by the fecal-oral route. The incubation period is 1-3 weeks. Typhoid can be confirmed by Widal test and symptoms related to it are high fever, low pulse rate, abdominal pain, frequent stools. 

The medical termination of pregnancy is advised under the following circumstances:

• If the pregnancy endangers the health (physical/mental) of the woman.
• If the child is malformed or handicapped
• In cases of rape
• If the girl is unmarried, consent of the guardian is required.
• In the case of mentally ill mothers

The process of formation of sperms is called spermatogenesis. It involves 3 phases- multiplication phase, growth phase, maturation phase.

• In multiplication phase, male germ cells also called as spermatogonia undergo mitotic divisions to form large number of spermatogonia.
• In growth phase, spermatogonia increases their size by accumulation of nutrition in the cytoplasm and are ready for meitoic division and the spermatocytes are called as primary spermatocytes with 46 chromosomes.

LAW OF DOMINANCE

The law of dominance states that one of the pairs of inherited traits will be dominant and the others recessive unless both the factors are recessive.

The dominant allele masks the effect of recessive allele. It explains the expression of only one of the parental characters in a monohybrid cross in F₁ and expression of both in F₂.

• Characters are controlled by discrete units called factors.
• In a dissimilar pair of factors one member of pair dominate the other. For example: allele of tallness (T) is dominant over allele of dwarf (t).

Animal husbandry is the agricultural practice of breeding and raising livestock.
Animal husbandry plays a major role in the welfare of humas in the following ways.

1It increases food production and caters to the increasing food demand.

2. It provides various animal products like milk, eggs, meat, wool, silk, honey etc used by the humans.

3. On the commercial aspect,  it also fetches a lot of money from export of the animal products.

4. Demand for aquatic foods especially fish and fish products has also been met by animal husbandry practice.

Interferon : These are proteins made and released by host cells in response to the presence of pathogens such as viruses, bacteria, parasites etc.

Role: It inhibits viral infections and stimulates the entire immune system to fight disease. It also regulates many kinds of cell functions.

DNA polymerase III is found in E.coli that helps in the replication process. It performs the 5’-3’ polymerase activity as well as 3’-5’ exonuclease activity. It has the ability to proofread the wrong nucleotides and substitutes it with the correct one.

• Antibiotics are used as drugs to treat infections because of their low toxicity for humans and animals.
• An antibiotic is a substance produced wholly or partly by chemical synthesis, which in low concentrations inhibits the growth or destroys microorganisms by intervening in their metabolic processes.
• In order to find chemicals this will affect the invading bacteria and not the host.
• Paul Ehrlich, a German bacteriologist, conceived this idea. He investigated arsenic based structures in order to produce less toxic substances for the treatment of syphilis.
• He developed the medicine, arsphenamine, known as salvarsan.
• Although salvarsan is toxic to human beings, its effect on the bacteria, spirochete, which causes syphilis, is much greater than on human beings.

When pregnancy occurs, high levels of progesterone and estrogens suppress the gonadotrophin (FSH). The latter is required for the development of new follicles. Thus, new menstrual cycle cannot be initiated as long as FSH secretion is suppressed. So, menstrual cycles are absent during pregnancy.

Post transcriptional modification of hnRNA in eukaryotes includes three event. Splicing is removal of introns from the primary transcript and ligation of exons to form a continuous sequence specifying a functional polypeptide. Capping of eukaryotic mRNAs refers to addition of 7-Methylguanosine to the 5’ end of almost all eukaryotic mRNAs in an unusual 5’,5’- triphosphate linkage. Tailing refers to cleavage of 3’ end and addition of 80 to 250 A residues to create a poly(A) tail.

Cannabinoids are obtained from the inflorescence of the plant Cannabis sativa. Marijuana, hashish, charas, ganja are some of the cannabinoids. These chemicals interact with cannabinoid receptors of the body, mainly present in the brain. Cardiovascular system is affected adversely.