Meiosis is a type of cell division that results in the formation of four daughter cells each with half the number of chromosomes as the parent cell.
Mitosis is the type of cell division that results in the formation of two daughter cells each with the same number of chromosomes as the parent cell.

Thalassemia is a hereditary condition that affects the blood which leads to an abnormal form of haemoglobin. Haemoglobin is an important protein molecule present in RBC that carries oxygen. This disorder leads to the destruction of RBC which leads to anaemia.

• It is caused due to absence or excess or abnormal arrangement of one or more chromosomes.
• Aneuploidy – failure of segregation of chromatids during cell division cycle results in the gain or loss of chromosome.
• Polyploidy – Failure of cytokinesis after telophase stage of cell division results in an increase in a whole set of chromosomes in an organism.
• Down’s syndrome – gain of extra copy of chromosome 21 (trisomy 21)
• It was first described by Langdon Down (1866).
• Affected individual is short with small round head, furrowed tongue and partially open mouth.
• Broad palm with characteristic palm crease.
• Physical, psychomotor and mental development is retarded.

Homeostasis is the ability to maintain internal stability in an organism in response to the environmental changes. The internal temperature of the human body is the best example of homeostasis.

Mendel selected a pea plant because of the following features.

(a) Peas have many visible contrasting characters such as tall/dwarf plants, round/wrinkled seeds, green/yellow pod, purple/white flowers, etc.
(b) Peas have bisexual flowers and therefore undergo self pollination easily. Thus, pea plants produce offsprings with same traits generation after generation.

(c) In pea plants, cross pollination can be easily achieved by emasculation in which the stamen of the flower is removed without affecting the pistil.

(d) Pea plants have a short life span and produce many seeds in one generation.

Water hyacinths are the only large aquatic herb that can float on the water unattached to the bottom. They float on bloated air-filled hollow leaf stalks. The leaves of free-floating water hyacinths are characterised by a bulbous swelling in a section of the petiole. The oxygen bubbles float to the surface of water and get released into the air which provides buoyancy.

Yes, pollen mother cell and microspore mother cell are the same, it is present in the pollen sac of anther. well no not exactly but Pollen mothercell divides meiotically to give rise to 4 microspores in form of tetrads that mature and separate to form pollen grains(4 pollengrains from each tetrad).

Spermatogenesis

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.
• In maturation phase- A primary spermatocyte completes the first meiotic division leading formation of two equal, haploid cells called secondary spermatocytes, which have only 23 chromosomes each and the secondary spermatocytes undergo the second meiotic division to produce four equal, haploid spermatids

any of the male reproductive cells released in the semen during ejaculation, consisting of a flattened egg-shaped head, a long neck, and a whiplike tail by which it moves to fertilize the female ovum

Tests used to confirm a syphilis infection include: Enzyme immunoassay (EIA) test. This blood test checks for syphilis antibodies. A positive EIA test should be confirmed with either the VDRL or RPR tests. Antibody tests are most commonly used. Antibody tests (serology)—these tests detect antibodies in the blood and sometimes in the cerebrospinal fluid (CSF). Two general types are available for syphilis testing, nontreponemal antibody test and treponemal antibody test (derived from the name of the bacterium). FTA-ABS is commonly used as a confirmatory test following positive VDRL or RPR test findings. FTA-ABS has a sensitivity of 84% for detecting primary syphilis infection and almost 100% sensitivity for detecting syphilis infection in other stages. Its specificity is 96%.

Butyric acid also known under the systematic name butanoic acid. Butyric acid is found in animal fat and plant oils, bovine milk, breast milk, butter, parmesan cheese, and as a product of anaerobic fermentation (including in the colon and as body odor, and vomit). Butyric acid has a taste somewhat like butter and an unpleasant odor. Butyrate is produced as end-product of a fermentation process solely performed by obligate anaerobic bacteria. Butyric Acid is a saturated short-chain fatty acid with a 4-carbon backbone. Butyric acid is commonly found in esterified form in animal fats and plant oils. The main species responsible for the production of vinegar belong to the genera Acetobacter, Gluconacetobacter, Gluconobacter and Komagataeibacter because of their high capacity to oxidise ethanol to acetic acid and high resistance to acetic acid. Acetic acid is a weak organic acid and its most common source is vinegar. It can also be prepared by oxidation of aldehydes and aerobic fermentation of carbohydrates. Anything you can let sour, as long as it'll undergo alcoholic fermentation first. Usually it's been vinegar, that is, sour wine. Acetic acid bacteria (AAB) are a group of Gram-negative bacteria which oxidize sugars or ethanol and produce acetic acid during fermentation. The acetic acid bacteria consist of 10 genera in the family Acetobacteraceae.

 If a marine fish is placed in a fresh water aquarium, then its chances of survival will diminish. This is because their bodies are adapted to high salt concentrations of the marine environment. In fresh water conditions, they are unable to regulate the water entering their body (through osmosis)

Because of water's relatively high boiling point, most water exists in a liquid state on Earth. Liquid water is needed by all living organisms

The rate of biomass production is called productivity.

Productivity is of two types-

• Primary productivity
• Secondary productivity.

A diploid cell is a cell that contains two sets of chromosomes. One set of chromosomes is donated from each parent. The diploid number is commonly abbreviated as 2n. For humans this equation would be 2n=46. Humans have 2 sets of 23 chromosomes leading to a total of 46 chromosomes.

Haploid cell is a cell that has only a single set of chromosomes. The cell contains only one member of each homologous pair of chromosomes (haploid number = n). For example - A  human germ cell (a sperm or an egg cell) is haploid, which means it contains only one of each of the 23 chromosomes of the human genome, or it only has half the diploid (2n) number of a human somatic cell (which is 46).

Seminal plasma is the fluid part of semen and is contributed by seminal vesicles, prostate gland and bulbourethral glands.

Seminal vesicles contribute fructose, citric acid and other nutrients as well as fibrinogen and prostaglandin. Secretions from prostate gland contain calcium ions, phosphate Ion, etc. and are alkaline in nature. Bubo urethral glands secrete alkaline mucus which is important for the lubrication of *****.

Raphe describes the intersection or seam in a tissue or organ between two separate parts, particularly when they were embryologically separate from each other. Commonly, it is used with reference to the structure forming the fused ends of two flat muscle sheets. Examples include: anococcygeal raphe. bulbospongiosus raphe.  The perineal raphe is a visible line or ridge of tissue on the male human body that extends from the **** through theperineum. This structure continues through the midline of the ******* (scrotal raphe) and upwards through the posterior midline aspect of the ***** (penile raphe).

Antipodals

• 3 cells at basal end of ovule
• Located at chalazal end

The polar nuclei are the two nuclei situated at the central position of the embryo sac. They together fuse with the male nucleus other than the one who fuses the egg. After fusion the polar nuclei form endosperm which acts as the food supply unit for the seeds in dormancy.

The vascular tissue system forms a strand of vascular tissues known as vascular strand or vascular cylinder.

The ovule is a small structure attached to the placenta by means of a stalk called funicle. The body of the ovule fuses with funicle in the region called hilum. Thus, hilum represents the junction between ovule and funicle. Each ovule has one or two protective envelopes called integuments.