Biology MCQs

Notes:
Protein digestion begins when you first start chewing. Your saliva contains two enzymes called amylase and lipase. They mostly break down carbohydrates and fats. Once a protein source reaches your stomach, hydrochloric acid and enzymes called proteases to break it down into shorter chains of amino acids.

Notes:
The functions of the stomach are:

1. It temporarily stores food
2. It contracts and relaxes to mix and break down food
3. It produces enzymes and other specialized cells to digest food

Thus, all the given statements are correct.

Notes:
The parathyroid glands secrete parathyroid hormone or parathormone. The parathyroid glands are two pairs of small, oval-shaped glands.

Notes:
The division of human eggs is holoblastic and unequal. Holoblastic cleavage is observed in eggs that have a moderate to the sparse amount of yolk. Holoblastic cleavage is the complete division of an isolecithal or microlecithal egg into blastomeres.

Notes:
An experimental cross of an individual organism of dominant phenotype but unknown genotype and an organism with a homozygous recessive genotype is known as a test cross.

Notes:
Bioethanol is produced by fermentation of residues from corn, potatoes, cereals, sugar beets, sugarcane and vegetables.

Notes:
A chromosome contains the specific DNA sequence, called the origin of replication, which is responsible for initiating replication. DNA ligase is an enzyme. It helps in binding the DNA. Termination sequence is the site where DNA replication ends while histones are the proteins around which DNA is wound.

Notes:
The recognition site is the sequence of DNA where the DNA is cleaved. The presence of more than one recognition site can result in multiple cuts within the DNA leading to DNA fragmentation. This would complicate the process of gene cloning.

Notes:
Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle. The word “prokaryotic” means “before nucleus.” Prokaryotes include two groups: bacteria and another group called archaea. In contrast, eukaryotic cells have a “true” nucleus containing their DNA.

Notes:
The Rock Dove (Columba livia) or Rock Pigeon, is a member of the bird family Columbidae (doves and pigeons). In common usage, this bird is often simply referred to as the “pigeon”. The species includes the domestic pigeon (including the fancy white pigeon).