Answer:
Internal Fertilization: Mammals,birds and reptiles in them the mode of fertilization is internal
External Fertilization: Amphibians and fishes used external fertilization.
Egg laying Animals;Birds,reptiles and some mammals platypus lays eggs.
Explanation:
Fertilization is a process in which a female egg (Ovum) and male egg (sperm) unite to form a zygote.A zygote is a fertilized egg which grows within an embryo.The process of fertilization is important in eukaryotes such as animals, humans,birds and plants. Fertilization divides a cell into many daughter cells by the process of mitosis and meiosis.It doubles the chromosome numbers.Fertilization are of two types internal and external.
Answer:
More than 7000 chemicals are present in tobacco smoke.
Explanation:
In these 7000 chemicals, 250 are harmful to the human body such as carbonmonoxide, ammonia and hydrogen cyanide etc. There are some chemicals that are found in tobacco smoke which causes cancer disease in human. About 69 chemicals out of 250 are present in tobacco smoke that causes cancer disease. So its consumption is dangerous for health.
