Correct Answer: C. begin to increase

Correct Answer: A. cross-breeding

Correct Answer: A. insects

Correct Answer: C) Coniferous forest

Explanation

In West Africa, there are different types of biomes, which are large areas with distinct plants, animals and climate. One of the options listed is not a major biome in West Africa. The options are Rain forest, Savanna, Coniferous forest, and Mangrove. Rainforest is a dense forest with high rainfall and diverse species of plants and animals. Savanna is a grassland with scattered trees and shrubs, and it is known for its large herds of grazing animals. Coniferous forest is a type of forest dominated by cone-bearing trees that are adapted to cold and dry conditions. Mangrove is a type of forest that grows in saltwater areas near the coast. Out of the options listed, Coniferous forest is not a major biome in West Africa. This is because Coniferous forests are typically found in colder regions with low rainfall, and West Africa is known for its warm and humid climate. It is important to understand the different types of biomes as they affect the distribution of plant and animal species. For example, the types of plants and animals found in a rainforest are different from those found in a savanna. This is due to the distinct climate and soil conditions in each biome.

Correct Answer: B. Thymine

Explanation

In DNA, the four nucleic acid basis are adenine, guanine, cytosine, and thymine. RNA has uracil instead of thymine. Adenine pairs with thymine in DNA and uracil in RNA. Cytosine and Guanine pair together in both. Deoxyribose and ribose are the 5-carbon sugars in DNA and RNA nucleotides, respectively.

Correct Answer: A. symbiotic nutrition

Correct Answer: C) thyroxin

Explanation

Cretinism is a condition that affects human growth and development. The question is asking what causes cretinism. The options provided are Vitamin A, insulin, thyroxin, and Vitamin C. To answer this question, we need to understand what cretinism is and what each of the options does in the human body. Cretinism is a condition that occurs when there is a deficiency of thyroxin hormone in the body. Thyroxin hormone is produced by the thyroid gland, which is located in the neck. Thyroxin hormone plays an important role in regulating the body's metabolism, growth, and development. When there is a deficiency of thyroxin hormone, it can lead to stunted growth, mental retardation, and other developmental problems. Option A, Vitamin A, is important for vision, immune system function, and skin health. It does not play a role in the production of thyroxin hormone, so it is not the cause of cretinism. Option B, insulin, is a hormone that regulates blood sugar levels in the body. Insulin does not play a role in the production of thyroxin hormone, so it is not the cause of cretinism. Option C, thyroxin, is the correct answer. As mentioned earlier, cretinism is caused by a deficiency of thyroxin hormone in the body. Option D, Vitamin C, is important for immune system function, wound healing, and collagen production. It does not play a role in the production of thyroxin hormone, so it is not the cause of cretinism. In summary, the correct answer to the question is Option C: thyroxin. Cretinism is caused by a deficiency of thyroxin hormone in the body.

Correct Answer: C. One seed leaf, petals in threes or group of thees and parallel venation of leaves

Correct Answer: A. 1:1

Explanation

The genotypic ratio is the ratio of the number of individuals with different genotypes. In this case, the genotypic ratio is 1:1

Correct Answer: A. there is free movement in animals while this is limited in plants