Correct Answer: A. Autocrine

Explanation

When a molecule binds to a receptor on a cell surface, it means that a signal has been received by that cell. In this case, the cell that sent the signal is the same cell that is receiving the signal. Autocrine signaling is the term that describes a cell sending a signal to itself (

Correct Answer: B. canines to tear up the meat

Correct Answer: A. Semi-circular canals

Correct Answer: D) Gene

Explanation

In Biology, hereditary characters are passed on from one generation to another through genes. Genes are the units of inheritance that carry the hereditary information from parents to offspring. In plants, the carrier of hereditary characters is the gene. The options in the question are: Cell, nucleus, chromosome, chloroplast, and gene. Cells are the basic unit of life, and they contain various organelles such as the nucleus, mitochondria, and chloroplasts. The nucleus is the control center of the cell and contains genetic material in the form of chromosomes. Chromosomes are thread-like structures made up of DNA that carry the genetic information. Chloroplasts are the organelles responsible for photosynthesis in plants. Out of the given options, the correct answer is D, gene. Genes are located on chromosomes and are responsible for the transmission of hereditary characters in plants. Although the nucleus and chromosomes play a crucial role in the transmission of hereditary characters, the actual carrier of the hereditary information is the gene. In conclusion, the carrier of the hereditary characters in plants is the gene, which is located on the chromosomes.

Correct Answer: D. they lack root hairs

Correct Answer: B. heart

Correct Answer: C. Protoplasm

Correct Answer: D. chitin

Correct Answer: C) Intercellular space

Explanation

The question is asking which part of a leaf contains air. It provides five options to choose from: guard cell, palisade layer, intercellular space, vascular bundle, and upper epidermis. First, it's important to understand the basic structure of a leaf. Leaves have an upper epidermis and a lower epidermis that protect the internal structures of the leaf. Between these two layers lies the mesophyll, which is where photosynthesis occurs. The mesophyll is divided into two layers: the palisade layer and the spongy layer. The palisade layer is a tightly packed layer of cells that contains many chloroplasts and is responsible for most of the photosynthesis in the leaf. The spongy layer is made up of loosely packed cells that allow for gas exchange. Now, let's look at the options provided in the question. Guard cells are specialized cells that control the opening and closing of stomata, which are small pores on the surface of leaves that allow for gas exchange. Palisade layers are a part of the mesophyll that contains many chloroplasts and is responsible for most of the photosynthesis in the leaf. Vascular bundles are the veins of the leaf that transport water and nutrients throughout the plant. The correct answer to the question is option C, intercellular space. Intercellular spaces are the air pockets that are found between cells in the spongy layer of the mesophyll. These spaces allow for the diffusion of gases, which is essential for photosynthesis. In summary, the structure of a leaf contains many different parts, including the upper and lower epidermis, the mesophyll (which is made up of the palisade and spongy layers), guard cells, and vascular bundles. The correct answer to this question is the intercellular space, which is found between cells in the spongy layer of the mesophyll and allows for gas exchange.

Correct Answer: C. chromosomes