It refers to making or crating new genes in form of mutation
in duplicates of old genes. It is also a mechanism in major way through new
genetic material is generated during evolution. The duplication happens in
event termed unequal crossing over or recombination between misaligned
homologous chromosomes during meiosis.
Answer:
every answer of yours is correct
The range of a set of data is the difference between the highest and lowest values in the set.
And to find the range, first order the data from least to greatest. Then subtract the smallest value from the largest value in the set.
Answer: 1. Sea urchins and sea otters
2. They are prey for carnivores.
3. Sea otters, star fish
Explanation:
Sea urchins and sea otters are carnivores as they eat on the flesh of starfish and sea urchins respectively.
Starfish feed on the kelp forests which are the producers in the food chain and the starfish is the primary consumer and prey for sea urchins. So, starfish and kelp forests are the prey in the marine ecosystem.
Keystone species is the one which controls the population of other inferior species in an ecosystem. Here, sea otters consume sea urchins so the population of sea urchins remained in control Starfish controls the population of kelp forest.
Answer:
a) i) Xylem
ii) Upper epidermis
iii) Stoma
iv) Chroloplast
v) Palisade cell layer
b) By a waxy layer on the cuticle of the leaf
Explanation:
The plant's leaves have a large surface area that is capable of absorbing sunlight. The plant's waxy layer in the surface of the leaf protects it from the loss of water, as well as of diseases caused by the entry of microorganisms. The palisade cell's surface is a single layer of cells underneath the upper epidermis that is adapted to absorb light energy.
The waxy layer is a primary physical barrier composed of insoluble polymers and lipids whose function is to protect the leaves against the entry of harmful organisms including virus, bacteria and fungus. Moreover, the plant's waxy cuticle is also a barrier that prevents the loss of water and solutes.
