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Alecsey [184]
3 years ago
7

During which era in earth's history were the first insects?

Biology
1 answer:
nordsb [41]3 years ago
6 0
According to the evolution theory, the first insects appeared about 400 million years BC in the Devonian Period. 
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After watching the video, how would you define the term ecological relationship? Are they always beneficial to organisms involve
dangina [55]

Answer:

There is no video but ecological relationship will be defined on a general note and it is not always beneficial to organisms.

Explanation:

In an ecosystem, organisms of the same or different species tend to interact with one another. This interaction is referred to as ECOLOGICAL RELATIONSHIP between the involved organisms. An ecological relationship can be of different types depending on the effect.

SYMBIOSIS is an ecological relationship between two organisms that interact together. SYMBIOSIS can either be mutualistic (both organisms benefit), parasitic (one organism loses and one gains), or commensalistic (one organism benefits and one neither benefits or loses). Another ecological relationship is PREDATION, where one organism called the PREDATOR feeds on part or all of another organism called PREY in order to obtain energy.

As stated above, some of the organisms involved in an ecological relationship benefits while others lose. Hence, it is not always a beneficial relationship to organisms.

7 0
3 years ago
Answer correctly 50 Points
Natali [406]

1. The main aim of the Human Genome Project was to determine the DNA Sequence of every human gene.

2. Variation in skin colour is an example of polygenic inheritance

This Human Karyotype is unusual because it has an extra chromosome at chromosome 21.

Klinefelters syndrome is shown in the second figure

Explanation:

1. The Human Genome Project's main goal was to sequence all the 30,000 genes and 3 million base pairs in their makeup for the early detection of diseases, gene therapy and molecular level studies.

2. Human skin colour is determined by the pigment melanin. The Dominant allele is responsible for dark colours as it produces more melanin. The melanocortin 1 receptor (MC1R) gene and Tyrosinase enzyme codes for the human skin colour. Polygenic inheritance are the traits which are controlled by one or more genes.

<u>figures:</u>

<u>The extra chro</u>mosome at the 21st chromosome pairs is called trisomy 21 or Down's Syndrome. It is due to the abnormal cell division/meiosis resulting in an extra X chromosome. This leads to thechanges the in physical development of  the individual.

Klinefelter's Syndrome: There are 47 chromosomes and 2 or more X chromosomes in this syndrome of males. The resulting male suffering from Klinefelter would be sterile and have poorly developed testicles.

7 0
2 years ago
Anthony is studying decent in a tribe in Africa he observed that in the tribe the children inherit land through their father’s s
ira [324]
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6 0
2 years ago
Read 2 more answers
Why are rabbits referred to as an introduced animal in Australia​
mezya [45]
European rabbits (Oryctolagus cuniculus) were introduced to Australia in the 18th century with the First Fleet and eventually became widespread. Such wild rabbit populations are a serious mammalian pest and invasive species in Australia causing millions of dollars of damage to crops.
6 0
3 years ago
What is gene regulation?
Alex_Xolod [135]
Gene regulation is the control of when and where proteins are made. 
Hope this helps :)
7 0
2 years ago
Read 2 more answers
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