Answer choices:
- A frame shift mutation in the X chromosome of a cheek cell
- A chromosomal mutation in the Y chromosome of a kidney cell
- A point mutation in the first chromosome of a sperm cell
- A substitution mutation in the third chromosome of a uterus cell
Answers:
A point mutation in the first chromosome of a sperm cell
Explanation:
Only mutations that affect the germ line are passed on to the next generation. Therefore, only mutations in the egg and sperm of an individual have the potential to affect the next generation.
Mutations in cheek cells, kidney cells, and uterus cells might cause cell death or cancer. This genetic material is not passed on to the next generation, only the egg and sperm contribute this material. Therefore, only mutations here will affect the generation.
Different structures and functions of roots
Explanation:
Roots are the underground descending non-green part of the plant.
Root functions: Anchorages the plant to the soil, absorbs water and nutrients from the soil.
Characteristics: Positively geotropic and hydrotropic, negatively phototropic; does not have nodes, internodes or stems.
Types:
- Tap root
- Adventitious root – fibrous, foliar and true adventitious roots
Structure and functions:
- Root cap or Calyptra: Cap-like structure covering the root tip
.
- Function: protects the meristematic tissues of the root, secretes mucilage which enhances the root tips to grow into the hard soil.
- Meristematic zone or growing point sub-terminal behind root cap. These cells are inverted and looks like a dome.
- Function – helps in the root growth by adding new cells to the root tip and other basal regions
- Zone of elongation behind the meristematic zone.
- Function – helps in elongation of the root
- Root hair zone: This is the zone of differentiation where cells differentiate into vascular tissues like phloem, xylem, endodermis, cortex etc.
- The main function of root hair is to increase the total surface area of root to facilitate more absorption of water and other nutrients from the soil
- Zone of maturation: the major and mature portion of a root.
- Function - lateral roots originates from this zone and radial differentiation leads to secondary growth.
thymine
adenine
cytosine
guanine
Explanation:
uracil is not because uracil is only RNA.
Answer:
a. the coordinated control of gene expression in bacteria
Explanation:
An operon in bacteria is a collection/cluster of genes that are under the control of a single promoter. It includes 3 components: a promoter, the genes and an operator. The operator is where a repressor binds, and the promoter is where transcription begins.
Operons allow organisms to control the expression of multiple genes in response to environmental cues
Answer:
0.1
Explanation:
The Net Reproduction per individual per unit time (r) can be calculated as (births-deaths)/population size
Given that:
Population size of mice = 1,000; Birth = 500; Death = 400,
Net reproduction rate (r) = (births-deaths)/population size
r = (500 – 400)/1000
r = 100/1000
r = 0.1
The Net reproduction per individual per unit time (r) is 0.1
