Question

Why aren't aged members removed from a population

a. explain the drop in fitness of older individuals (two hypothesis)

b. why are younger people responding to cancer more strongly (cancer is found more commonly in older people) (include immunology explanations, apoptosis of cells or genes, DNA repair protein levels) (provide examples)

c. Is a big older aged population r-selected or k-selected

Answer 1

(a) The study found that the reduction in physical activity level and functional fitness was equal for both men and women and was due to ageing process. These differences between young and old elderly people were due to the reduction of muscle strength in both upper and lower limbs and changes in body fat percentage, flexibility , agility and endurance.

(b) Cancer starts when cells begin to grow out of control . Cells in nearly any part of the body can become cancer and spread to other areas of body.

For statistics purposes, cancer in young adults, are often thought of as those that start between the ages of 20 and 39.

Cancer is not common in young adults, but a wide variety of cancer types can occur in this age range, treating these cancers can be challenging for a number of reasons.

A small portion are strongly influenced by changes (mutations) in a person's genes that they inherit from their parents.

The types of cancers that occur in young adults are mix of many of the types that can develop in children, teens and other adults. They are:

Breast cancer

Lymphomas

Melanoma

Sarcomas

Cancer of the female genital tract (cervix and ovary)

Thyroid

Testicular cancer

Colorectal cancer

Leukemia

Brain and spinal cord tumors

(c) Older aged population are K- selected, such as man, most individuals live to old age . features of K - selected are-

Large size of organisms

energy used to make each individual is high

few offssprings are produced

late maturity

long life expectancy

individuals can reproduce more than once in their lifetime

comes under survivorship pattern in which most individuals live to near the maximum life span.