Correct Answer: D. manufactured their own food

Correct Answer: B. by synthesizing simple substances using energy

Correct Answer: D) in the ovary of a flower

Explanation

This Biology question is asking about where cells undergoing meiosis can be seen. Meiosis is a process of cell division that produces four haploid cells, each with half the number of chromosomes as the parent cell. The question is asking which structure will contain cells undergoing meiosis. Option A suggests that cells undergoing meiosis will be seen at the apices of stem and root. The apices are the tips of the stem and root, where growth occurs. However, meiosis usually occurs in reproductive structures, so option A is unlikely. Option B suggests that cells undergoing meiosis will be seen in the cortex of the stem. The cortex is the outer layer of the stem, and it contains various types of cells. However, meiosis is unlikely to occur in the cortex of the stem. Option C suggests that cells undergoing meiosis will be seen in the palisade mesophyll of the leaf. The palisade mesophyll is the layer of elongated cells located beneath the upper epidermis of a leaf. However, meiosis is unlikely to occur in the palisade mesophyll. Option D suggests that cells undergoing meiosis will be seen in the ovary of a flower, and this is the correct option. The ovary is the female reproductive organ of a flower that contains ovules, which will later become seeds if fertilized. Meiosis occurs during the formation of the ovules. In conclusion, cells undergoing meiosis will be seen in the ovary of a flower. Meiosis occurs during the formation of the ovules, which will later become seeds if fertilized.

Correct Answer: B. adrenaline

Correct Answer: B) Chromatin threads

Explanation

This Biology question is asking where genes are carried in a cell. Genes are responsible for carrying genetic information and are found within the DNA molecule. The options given are Nuclear membrane, Chromatin threads, lysosomes, and Mitochondria. To answer this question, we need to know that genes are located within the nucleus of a cell. The nucleus is surrounded by a nuclear membrane which separates it from the rest of the cell. Within the nucleus, the DNA molecule is wrapped around proteins called histones, forming a structure called chromatin. Therefore, the correct answer to this question is Option B: Chromatin threads. This is because chromatin is the structure that carries the genes in a cell. Chromatin is found within the nucleus of a cell and is responsible for carrying genetic information. It is important to note that while lysosomes and mitochondria are important organelles in a cell, they are not responsible for carrying genes. For more information, please see the recommended textbooks

Correct Answer: D. Body defence

Explanation

(a)The general arrangement of the viscera of man or rabbit shows that the diaphragm divides the trunk into two unequal parts namely, the upper chest cavity and the lower abdominal cavity. The chest cavity is enclosed or encircled by the ribs in which the lungs and the heart lie. The gullet runs down behind the mouth or buccal cavity through the whole length of the thoracic cavity, through the diaphragm. The liver lies below the diaphragm which over-laps a large portion of the stomach. The stomach leads to the small intestine which itself leads to the large intestine. The large intestine forms the caecum at one end and continues to form the rectum at the other end which finally terminates at the anus which lies at the posterior end of the trunk. Very close to the stomach are the pancreas and spleen. At the back of the abdominal cavity, we have a pair of kidneys. In male, the male part of the vasa diferensia are seen at the posterior region in close position with the bladder and ureter. In female, ovaries lie near the kidney, and the oviducts lead to the uterus or womb which is in the lower part of the abdominal cavity or behind the urinary bladder.

(b)(i)Hydra feeds mainly on small aquatic organisms.

-Food is captured by the help of nematocysts, borne on the tentacles.

-The food is then taken into the wide mouth by the tentacle.

-Here enzymes are secreted by the gland cells.

-digested extra cellularly and partially absorbed into endodermal cells.

-Here digestion is completed intra-cellularly.

(ii) Amoeba feeds on micro-organisms, e.g. diaton or organic particles. During feeding, it engulfs the food particles by forming cup shape. When the two ends of the pseudopodia touch, they fuse and enclose the food with little amount or drop of water and these form a food vacuole. The food is digested and absorbed here.

Explanation

(a) The process of perceiving smell

• Chemical substances/odour carried in the air pass through the air/nasal cavity
• The molecules dissolve in the moist membrane of the nasal cavity
• Sensory cells are stimulated
• Impulses are formed
• which pass through the nerves ending to the olfactory nerves
• which pass into the cerebrum of the brain/brain
• The brain interprets the impulses
• And the sensation of smell is produced/smell is perceived

(b)Adaptive features of the egg of a domestic fowl;

Porous: shell; for gaseous exchange/provides shelter/ protects the embryo against mechanical damage/ desiccation

Shell membranes; allow gaseous exchange/for protection

Yolk; contains high level of proteins and fats/provides food for embryonic-growth

Egg white/albumen;consists of water to absorb shock/ proteins/food

Air space;provides surface for gaseous exchange Chalaza; holds the yolk/embryo in position.

(c)i. Autotrophs: Organisms that do not rely on other organisms for food/they manufacture their own food; from using simple inorganic compounds; can be chernosyn-thetic/photosynthetic

ii. Examples of unicellular autotrophs Clamydomonas; Euglena; chemosynthetic; bacteria/ sulphur, bacteria; blue-green; algae/Anabaena; Nostoc/ Oscillatoria; Chlorella diatoms; Nitrosomonas; Nitrobacteria

(d) Functions of WHO

1. provides grants for medical research
2. Improves public health/promotes environmental health
3. prevents the spread of diseases vaccination
4. provides vaccines/drugs in cases of emergencies
5. Informs/creates awareness/educates the public of any research findings/outbreak of diseases
6. Assists by sending medical personnel/logistical sup-port to countries upon request
7. Helps in the training of medical personnel
8. keeps health statistics
9. promotes nutritional/sanitary products.

(e) Examples of plants and animals that live in fresh water pond

Plants: Water arum; diatoms; Ceratophyllum/hornwort; utricularia/bladderwort. Arrowhead/sedge; Pistia; Salvinia/water fern; water lily; wolffish/duckweed any other correctly.

Animals: Cyclops; Daphnia/water flea; Hippopotamus; crocodile; water snake; tadpoles; pond skaters; zooplanktons; mosquito larvae; water bugs; water scorpions; leeches; water snails; catfish/Tilapia fishes etc.

(f) Differences between skin of a mammal and epidermis of leaf

(g) Type of competition on

(i) Plot A: intra specific/intra species competition

(ii) Plot B: interspecific/interspecies competition

Correct Answer: C. populations of different species living together and interacting with each other in one habitat

Correct Answer: A. vasodilation