Answer:
Four daughter cells are produced each with 40 chromosomes. The daughter cells would exhibit genetic variations and would not be genetically identical to each other.
Explanation:
Meiosis is a cell division that forms four daughter cells from one parent cell as two sequential division meiosis I and meiosis II do not include any DNA replication between them. Crossing over during prophase-I of meiosis-I includes the exchange of genetic segments and occurs between the homologous chromosomes. It produces new gene combinations in the daughter cells which were otherwise not present in the parent cell.
Since there is no DNA replication between meiosis I and meiosis II, the daughter cells have half the number of the chromosomes compared to the parent cell. This occurs as homologous chromosomes move towards the opposite pole during anaphase I.
Therefore, a parent cell with 80 chromosomes will make a total of 4 daughter cells by meiosis. Each daughter cell would have 40 chromosomes. These daughter cells would have some new gene combinations and would be genetically dissimilar among themselves.
Correct answer:
"<span>B- homologous chromosomes join together to form tetrads during prophase I"
</span>It is during prophase I that homologous chromosomes join together (<span>synapsis)</span> and form tetrads - four chromatids are together in the new structure of two chromosomes - and this is the reason why crossing-over occurs in this phase. It is in this tetrad that both arms of both chromosomes may crossover and matching regions exchange places. This process results in homologous chromosomes recombination leading to genetic variability.
Limiting factors, or things in the environment that can lower the population growth rate, include low food supply and lack of space. When organisms face limiting factors, they show logistic type of growth (S-curve).
Options for the question have not been given. They are as follows:
type of soil
type of plants
exposure to sunlight
method for measuring the growth
Answer:
exposure to sunlight
Explanation:
A scientific experiment has an experimental group and a control group. Control group is included to omit any error in results due to the factors other than the variable factor. Experimental group is the one exposed to different levels of the variable factor.
Here, Carlo wants to determine the the effect of day length on plants' growth. The test variable here is thus the duration of sunlight. In experimental group, this duration will be changed to determine its effect. In control group it will be kept constant so that results from other factors can be excluded from the observed experimental result.
