Answer:
Part A: Proteins are made from amino acid monomers. There are 20 different types of amino acids which make up all the proteins of the body. The amino acids are made up of a carbon atom which is joined to an amino group, a carboxyl group and a variant group, known as R. Nucleic acids are made up of 5 carbon sugar, phosphate group and nitrogenous bases. Hence, nucleic acids are made up of nucleotides.
Part B: Protiens are important molecule which carry out various functions of the body. They are involved in regulation of various body process. Some proteins are involved in the transportation of various molecules. Other type of proteins are involved in various immune functions and hence protect the body. For example, antibodies are proteins which defend the body against pathogens.
Nucleic acids are involved in the storing and expressing of genetic information. They also direct the body for protein synthesis.
Answer:
C, a long absolute refractory period.
Explanation:
Tetanus is not possible in cardiac muscle tissue because cardiac cells have longer action potentials and a very long refractory period compared to other cells. This helps prevent the heart from cramping and seizing up.
Answer:
Man's genotype: Bbdd
Woman's genotype: bbDd
First child's genotype: Bbdd
Second child's genotype: bbDd
Explanation:
This is a dihybrid cross involving two genes; one coding for eye color and the other for hair color in humans. The allele for brown eye (B) is dominant over the allele for blue eyes (b) in the first gene while the allele for dark hair (D) is dominant over the allele for red hair (d) in the second gene.
According to the question, A man with brown eyes and red hair will possibly possess genotypes: BBdd or Bbdd while a woman with blue eyes and dark hair will possibly have genotype: bbDD or bbDd. Considering the fact that they produced children with recessive traits for both gene (blue eyes and red hair), it means that they are heterozygous for their dominant trait. This means that the ideal genotype for the man is Bbdd since he will produce gametes containing B and b alleles for the first gene while the ideal genotype for the woman is bbDd since it will produce gametes with D and d allele for the second gene.
Hence, a child with brown eyes and red hair will possess genotype: Bbdd since he/she cannot receive two dominant alleles for the first gene from both parents. A child with blue eyes and dark hair will have genotype: bbDd since he/she cannot receive two dominant alleles of the second gene from both parents.
Answer:
Diffusion is the process in which molecules and ions move from a region of high concentration to low concentration. Its also how cells transport waste out of the cell and nutrients into it hence being very crucial. Diffusion also occurs without the expenditure of extra energy using a procedure known as passive transport. (Osmosis is a form of diffusion but deals with water exclusively).
Examples of where diffusion is important;
In the intestines - Digested food molecules such as amino acids and glucose move down the concentration gradient from the intestine into the bloodstream. Wastes such as carbon dioxide or urea travel via diffusion from the body's cells to the bloodstream.
Osmosis plays a major role in living organisms. It aids in the transportation of nutrients from cells to cells and also helps to remove the waste's metabolic products from the cell. The purification of blood in the kidneys is also dependent on the process of osmosis.
